How Loud is Too Loud? (Cal Games)

[Richard Wallace]

Originally Posted by KenWittlief

Everyone knows that electronic are pumped full of smoke. When the smoke leaks out electronics stop working.

Most people dont realize that mechanical parts are pumped full of noise. This is why they are made on very noisy machines. ...

By this logic, electronics should be made in smokehouses, like bacon or country hams.

[eugenebrooks]

Originally Posted by Richard

By this logic, electronics should be made in smokehouses, like bacon or country hams.

The smoke gets into the electronics with you solder the connections.

Eugene

[Richard Wallace]

Originally Posted by eugenebrooks

The smoke gets into the electronics with you solder the connections.

So lead-free electronics should contain more smoke, since they are soldered at higher temperatures, right?

[AdamHeard]

Is it also safe to assume that batteris only have a certain amount of sparks, and after that they don't work anymore?

[Greg Marra]

To get back to the original question of "How Loud is Too Loud?".

This loud:
|----------------------|*


Just use common sense. If it sounds like something is going to break, try to find where the problem is and correct it before it is an issue.

*(not to scale)

[artdutra04]

To use some Jeff Foxworthy logic...

When the police show up for night-time noise violation laws even though it's the middle of the day,
you might have a shooter that's too loud.

When the sound waves from your robot can register on the Richter scale,
you might have a shooter that's too loud.

When your drive team has bleeding ears after a match,
you might have a shooter that's too loud.

When the CIA shows up to confiscate your robot to use in Iraq to "smoke" terrorists out of buildings,
you might have a shooter that's too loud.

When a deaf spectator shows up and tells you to keep the noise down,
you might have a shooter that's too loud.


For your actual robot, use your best judgement. Try to see if anything can be fixed, tightened, etc. You also might want to try lubing the moving joints, and then run it for several minutes to break it in.

[JaneYoung]

What did you say?

(j/k)

EDIT: Our ball lift made a significant amount of noise this past year and I was impressed. And, my fingers were comfortable in my ears at times.

[KenWittlief]

WHAT?


If you are really concerned about the noise level itself borrow a dB meter from someone and measure the levels.

There are safety standards for noise levels and hearing damage. If your robot is loud enough to cause hearing damage then people standing nearby would need earplugs, and you should not run the shooter in the pit area.

[Billfred]

See, this is why I bring earplugs to FIRST events. (And you thought it was because I usually wind up near SPAM.)

I might suggest a rule that MIT's 2.007 course uses in their competition, known as the Naked Phone Booth Rule. Basically, if you wouldn't want to be in a phone booth with your device while naked (for two minutes, for our purposes), it's probably not a good idea to use it.

[eugenebrooks]

On a serious note, refer to the table linked to below.
http://www.occupationalhearingloss.c...aring_loss.htm

Under OSHA rules, no exposure above 115 dBA is allowed, however short.

So, this answers the question: How Loud is Too Loud?
If you have concerns, borrow or buy a sound level meter.

Yes, there will be a sound meter available at the Cal Games...

Eugene
(President of the WRRF)

[=Martin=Taylor=]

Originally Posted by eugenebrooks

On a serious note, refer to the table linked to below.
http://www.occupationalhearingloss.c...aring_loss.htm

Under OSHA rules, no exposure above 115 dBA is allowed, however short.

So, this answers the question: How Loud is Too Loud?
If you have concerns, borrow or buy a sound level meter.

Yes, there will be a sound meter available at the Cal Games...

Eugene
(President of the WRRF)

Thanks that's really helpful. I would say our robot measures somewhere around the 90 level

Although we haven't found a solution to the problem (a five day solution that is ) we have managed to adjust our shooter so that we only have to reach "jackhammer speed" for a very short time.

As for metal fatigue it has surprisingly held together quite nicely and there are no visible signs of damage.

[eugenebrooks]

Originally Posted by Hachiban VIII

Thanks that's really helpful. I would say our robot measures somewhere around the 90 level

Although we haven't found a solution to the problem (a five day solution that is ) we have managed to adjust our shooter so that we only have to reach "jackhammer speed" for a very short time.

As for metal fatigue it has surprisingly held together quite nicely and there are no visible signs of damage.

Only 90 dbA?, you can run that all day and we will call it entertainment!


Eugene

[KenWittlief]

Originally Posted by Hachiban VIII

...Although we haven't found a solution to the problem (a five day solution that is ) we have managed to adjust our shooter so that we only have to reach "jackhammer speed" for a very short time.

As for metal fatigue it has surprisingly held together quite nicely and there are no visible signs of damage.

If you think the problem is your shooter is out of balance it should be relatively easy to eyeball the system and see where it is not symetrical about the center of rotation

and to guesstimate the amount of weight you would have to add to the other side to balance it - like they do with the lead weights on car tires.

regarding metal fatigue, I dont think you will see any visable signs until something breaks. After a part has failed an experienced M.E. can look at the break and tell why it failed (crystalized, sheared, cut...)

[Al Skierkiewicz]

Originally Posted by eugenebrooks

On a serious note, refer to the table linked to below.
http://www.occupationalhearingloss.c...aring_loss.htm

Under OSHA rules, no exposure above 115 dBA is allowed, however short.

So, this answers the question: How Loud is Too Loud?
If you have concerns, borrow or buy a sound level meter.

Yes, there will be a sound meter available at the Cal Games...

Eugene
(President of the WRRF)

This is a good explanation but adding to this, the "A" scale is a frequency dependent curve that tries to approximate the inverse of human hearing sensitivity. As such it is less sensitive to areas where the human hearing is less sensitive. However, the offending noise is still there.
Many venues and outdoor arenas are now instituting noise level ceilings on performances. 110 dBA seems to be the defacto standard but the measurement is still an issue. Sounds decrease by the inverse square law with distance. So the issue is where do you measure the sound level. In arenas, it is acceptable to take an average of the seating area but any seat that exceeds the standard should be corrected by some means to come into compliance. Outdoor venues have to comply with neighborhood standards such that sound levels at the closest house must stay within local ordinance for the time of day. (local sound level ordinances vary between daytime and nighttime.) With a standard FRC playing field the drivers have less exposure than the judges and field people.

[Al Skierkiewicz]

I have always been of the opinion that if the mechanicals are making noise they are trying to talk to you. I would listen and try to determine the problem. It might just be that at speed a part of the mechanism is hitting another part as in something is just slightly out of alignment. Look for wear spots on your rotating parts. Could be that the sprockets are not parallel and in the same plane. The chain would make a distinctive knock each time a sprocket tooth attempts to engage a chain link. The faster the speed the more (and louder) the knocks.